I have made another one of these cards - in different colours and designs - but I don't think it would have arrived yet so will have to wait to put it on here.
I got the idea for this from a bought card that another friend received, and thought that I liked the idea so went home and had a play with sizings and folds until I was happy with the base.
And just for you Jacqui :) I remembered to write down my measurements:
Start with a sheet 10" x 6" then score and fold along the 10" side at 2", 3", 5", & 7" - almost like making a step card, only sideways.
You could make it 8" long and score at 2", 3", 5" & 6" but that leaves the last panel only 2" long instead of 3" and I preferred the wider panel for putting more on.